1. Field of the Invention
This invention relates to agitators for the dispersion of a fluid in a liquid.
2. Description of the Related Art
The invention is particularly concerned with an agitator of the kind disclosed in our prior EP-A-234768 which discloses an agitator assembly for use in dispersing fluids in liquids, the assembly including a rotor provided with scoop shaped blades oriented with the mouths of the scoops facing the direction of rotation of the rotor and arranged so as to impart radial and/or axial flow to the liquid, the blades being so shaped as to minimize fluid cavity formation at the trailing side thereof (a fluid cavity being an accumulation of the lighter phase at the trailing side of the blades where low pressure regions such as vortices can develop).
In some circumstances, there is a requirement for the blades to be set at an angle of attack such that one end of the blade leads the other blade end in the direction of motion of the blade. EP-A-234768 refers to the possibility of setting the blades at an attack angle provided that the attack angle is not so great as to give rise to the formation of substantial vortices.